The fundamental nature of acceleration sensitivity

In this paper, the fundamental nature of acceleration sensitivity is reviewed and clarified. The driving factor behind the acceleration-induced frequency shift is shown to be the deformation of the resonator. The deformation drives two effects: an essentially linear change in the frequency determining dimensions of the resonator, and an essentially nonlinear effect of changing the velocity of the propagating wave. The basic properties of acceleration sensitivity are illustrated through the simple examples of "BAW in a box" and "STW in a box". These examples serve to clarify a number of concepts, including the role of mode shape and the basic difference between the bulk acoustic wave and acoustic surface wave cases. Finally, these basic understandings are extended to other cases such as BAW microresonators.